1. Technical Field
The present disclosure relates to an outdoor unit for an air-conditioning apparatus, and an air-conditioning apparatus.
2. Related Art
Heretofore, an air-conditioning apparatus having at least one outdoor unit and a plurality of indoor units has been known. The indoor units are connected in parallel to the outdoor unit via a plurality of refrigerant pipes. The air-conditioning apparatus may be a so-called multi-air-conditioning apparatus in which all of the indoor units can perform a cooling operation or a heating operation simultaneously. The air-conditioning apparatus is capable of allowing the indoor units to be individually set to (or select) either a cooling operation or a heating operation and allowing them to be simultaneously operated (a so-called “cooling/heating-free operation”).
Such an air-conditioning apparatus is described in, for example, JP-A-2004-286253 (Patent Document 1). This air-conditioning apparatus is provided with one outdoor unit, two indoor units, and two electromagnetic valve units. The outdoor unit is provided with a compressor, an accumulator, an oil separator, a receiver tank, and two outdoor heat exchangers. The outdoor unit also includes an outdoor expansion valve, a discharge valve, and an intake valve coupled to each of the outdoor heat exchangers. Each of the indoor units is provided with an indoor heat exchanger. Each of the electromagnetic valve units is provided with two electromagnetic valves. The electromagnetic valve units switch the couplings of the respective indoor heat exchangers to the discharge side (high-pressure side) of the compressor or the intake side (low-pressure side) of the compressor.
In the air-conditioning apparatus disclosed in Patent Document 1, the outdoor unit, the indoor units, and the electromagnetic valve units are coupled via refrigerant pipes as follows. A discharge pipe coupled to the discharge side of the compressor is coupled to the oil separator and branched therefrom. One branch pipe is coupled to the outdoor heat exchangers via the discharge valves. The other branch pipe is coupled to the indoor heat exchangers via the electromagnetic valve units. The discharge pipe and the branch pipes constitute a high-pressure gas pipe.
An intake pipe coupled to the intake side of the compressor is coupled to the accumulator and branched therefrom. One branch pipe from the accumulator is coupled to the outdoor heat exchangers via the intake valves. The other branch pipe from the accumulator is coupled to the indoor heat exchangers via the electromagnetic valve units. The intake pipe and the branch pipes constitute a low-pressure gas pipe.
The outdoor heat exchangers each have two coupling ports. To one of the coupling ports, the discharge valves and the intake valves are coupled. To the other of the coupling ports, one end of a branched refrigerant pipe is coupled via the outdoor expansion valves. The other end of the refrigerant pipe is coupled to the receiver tank and branched therefrom. The branch pipes from the receiver tank are coupled to the coupling ports of the indoor heat exchangers on the side on which the electromagnetic valve units are not coupled. The refrigerant pipe and the branch pipes constitute a liquid pipe.
In the air-conditioning apparatus described above, the coupling between the indoor heat exchangers and the compressor is switched by opening or closing the electromagnetic valves of the electromagnetic valve units. Namely, by opening or closing the electromagnetic valves, the coupling between the indoor heat exchangers and the discharge side or intake side of the compressor is switched. Thus, each of the indoor heat exchangers can be caused to individually serve as a condenser or an evaporator. Thus, the cooling operation or the heating operation can be selected for the individual indoor units while the indoor units are simultaneously operated.